The unsettled weather over the northeast today is expected to move southwest to be in the central interior, the trough once again rotating around high pressure.
This trough will form the focus of more widespread showers and thunderstorms from Tuesday into Wednesday and while there is some model divergence, the risk of increased rainfall activity for later this week is still high, with heavy falls for some areas over the southeast and east.
Western areas may remain dry for now and hot with less humidity west of the trough.
Lets take a look
Rainfall Next 10 Days
Rainfall is expected to be relatively scattered and uneven during the coming few days, that summer rainfall will continue to mean some areas get a deluge and others missing out. But mid to late week, central and eastern areas will see more widespread rainfall with locally heavy falls over the coastal areas mainly south of Sydney through to Gippsland in Victoria and possibly inland to the GDR. But it will come down to the location of the trough embedded in the easterly winds. The showers clear the inland into the next weekend but the coast remains fairly unstable. The far west looking fairly dry and warm.
Thunderstorm Forecast Monday
Thunderstorms are forecast to develop in a broad zone through central areas west of the divide, with a 50/50 chance of storms in this zone turning severe with damaging winds and heavy rainfall leading to flash flooding. Large hail is a very low risk for now, but will be reviewed in the morning. The storm activity commences from 2pm through to 10pm and diminishes at night.
Flash Flood Risk Monday
Flash flooding due to slow storm motion and a decent slab of moisture through the atmosphere remains a low to moderate risk on Monday afternoon.
Damaging Winds Monday
Damaging winds are also a low to moderate risk over the inland west of the divide during the afternoon and evening with the heavier thunderstorms.
Large Hail Risk Monday
Large hail is a low risk over a broad area with strong pulse storms during the afternoon and evening.
DATA- You can see the GFS and CMC in the video.
00Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days
The pattern is fairly complex, low confidence and that means that your forecast will change from run to run, quite wildly in the next few days. Note the areas of interest will be the storm outbreak over the southeast and east of the nation mid week that could a spawn a heavy rainfall event on the NSW or VIC coast. The tropical weather is becoming more dynamic as we have seen today and the west is hot and dry with a heatwave underway and that may spread eastwards this coming weekend into SA and then VIC.
00Z Euro - Precipitable Water Values - Next 10 Days
The moisture is expected to be reserved over the northern and eastern parts of the nation and that is where you will find the rainfall. The amount you see will come down to the position of low pressure over the north and the east and where the monsoon enters in the medium term, which we will not know for about 2 days. it is a tricky forecast. The west of the nation looks drier under high pressure and that will extend into SA and western NSW and VIC.
00Z Euro - Rainfall Accumulation - Next 10 Days
I am leaning with this solution - I do think the tropical weather will change drastically from run to run. That will impact the rainfall forecasts down the track for southern and eastern Australia.
A closer look in - the rainfall amounts will vary from location with the thunderstorm in place and some of these could drop 50mm in a sitting, the west could well be dry for a while.
More details coming up in the rainfall wrap after 9pm EDT and that will be an interesting read.